ES2899607T3 - Transmission and reception unit for a multi-beam antenna and a multi-beam antenna - Google Patents

Abstract

Emission and reception assembly (20) for a multi-beam antenna (12), including the antenna (12) in addition to a communication module (22), such that the assembly (22) comprises: - a plurality of radiating elements (32A,...,32F) forming a radiating surface (S), each radiating element (32A,...,32F) being capable of emitting and receiving electromagnetic signals downstream of the radiating surface (S); - an emission distribution network (41) arranged upstream of the radiating surface (S) and including a plurality of emission ports, each emission port being connected to a radiating element (32A,...,32F) by an emission waveguide (45A,...,45F) and capable of emitting through the corresponding radiating element (32A,...,32F) an electromagnetic signal formed from an electromagnetic signal coming from the communication module ( 22); - a receiving distribution network (42) arranged upstream of the radiating surface (S) and including a plurality of receiving ports (50A, 50B), a plurality of low noise amplifiers (55A, 55B, 55C) and interconnection means (56) of each receiving port (50A, 50B) for at least one low noise amplifier (55A, 55B, 55C), such that each receiving port (50A, 50B) is connected to a radiating element (32A,...,32F) by a receiving waveguide (47A,...,47F) and is capable of receiving each electromagnetic signal coming from the corresponding radiating element (32A,...,32F) and transmitting it to the associated low noise amplifier (55A, B, 55C) to obtain an amplified electromagnetic signal destined for the communication module (22); the reception distribution network (42) and the radiating elements (32A, 32F) are thermally decoupled, characterized in that: - the emission distribution network (41) and the reception distribution network (42) are different from each other and they are arranged in the same box (34) different from the communication module (22); and in that the receiving waveguides (47A,...,47F) are made of a heat insulating material capable of thermally isolating the low noise amplifiers (55A, 55B, 55C) from the radiating elements (32A,..., 32F).

Description

DESCRIPTION

Transmission and reception unit for a multi-beam antenna and a multi-beam antenna

[0001] The present invention relates to a transmission and reception assembly for a multi-beam antenna.

[0002] The present invention also relates to a multi-beam antenna including said assembly.

[0003] In a manner known per se, the term "multi-beam antenna" designates an antenna comprising several radiating elements. Each of these elements is capable of receiving and/or emitting a beam of electromagnetic waves presenting an elementary signal that forms part of a more complex signal received by the antenna or intended to be emitted by it.

[0004] Some multi-beam antennas, especially those used in the field of satellite telecommunications, use a large number of radiating elements, which makes it possible to increase the technical performance of these antennas.

[0005] For this purpose, mention may be made, for example, of multi-beam antennas such as those described in documents US 2005/052333 A1 and US 2014/194293 A1.

[0006] In general, in this type of multi-beam antenna, the radiating elements are arranged in front of a reflector located outside the satellite and are connected to the other components of the antenna by waveguides that have rigid structures.

[0007] Furthermore, it is usual to place these other components in the internal part of the satellite, that is, in its payload. This action has in particular the purpose of thermally isolating the radiating elements that generally have a so-called hot zone of the antenna from the other components that must remain in a so-called cold zone, in order to minimize performance losses of the antenna.

[0008] Among the aforementioned components, a network for the distribution of waveguides in emission that allows the formation of a plurality of elemental signals to be emitted through the radiating elements and a network for the distribution of waveguides in reception that allows process elementary signals received by the radiating elements.

[0009] The receiving waveguide distribution network generally includes a plurality of amplifiers thus making it possible to amplify the elementary signals received by the radiating elements.

[0010] It is thus understood that, with the increase in the number of radiating elements, the architecture of said multi-beam antenna becomes considerably more complicated.

[0011] In fact, when this number increases, it is necessary to increase the number of waveguides, which translates into an increase in the complexity of routing the waveguides to the corresponding distribution networks and, more generally, by an increase in antenna costs. This complexity can further degrade the performances of the multi-beam antenna.

[0012] The object of the present invention is to propose an assembly for a multi-beam antenna that makes it possible to reduce the use of waveguides even when the number of radiating elements is large and without degradation of the performance of the antenna.

[0013] To this end, the object of the present invention is a transmission and reception assembly according to claim 1.

[0014] According to other advantageous aspects of the invention, the assembly comprises one or more of the characteristics of claims 2 to 10, taken in isolation or according to all technically possible combinations.

[0015] The present invention also has as its object a multi-beam antenna according to claim 11.

[0016] According to other advantageous aspects of the invention, the antenna comprises the feature of claim 12.

[0017] These characteristics and advantages of the invention will emerge from reading the description that follows, given solely by way of non-limiting example and made with reference to the attached drawings, in which:

Figure 1 is a schematic view of a satellite including a multi-beam antenna according to the invention; Figure 2 is a schematic view of the multi-beam antenna of Figure 1, the multi-beam antenna including a box comprising in particular a transmission distribution network and a reception distribution network;

figure 3 is a detailed schematic view of the box of figure 2; and

- figure 4 is a detailed schematic view of the distribution network in reception of the box of figure 3.

[0018] The satellite 10 of Figure 1 is, for example, a telecommunications satellite arranged in an Earth orbit and capable of communicating with one or several terrestrial centers by emitting and receiving electromagnetic signals through the multi-beam antenna 12.

[0019] The satellite 10 has an internal part 14 delimited by a satellite body 16. The internal part 14 includes in particular a payload 18.

[0020] In a manner known per se, the payload 18 includes equipment that ensures the mission of the satellite 12 and is protected, especially thermally, from outer space by the body 16.

[0021] In the remainder of the description, "outside the satellite" means the space outside the body of the satellite 16.

[0022] The antenna 12 is arranged partially on the outside of the satellite 10 and partially on its internal part 14 as will be explained below.

[0023] Referring to Figure 2, the antenna 12 includes an electromagnetic signal emission and reception assembly 20, a communication module 22 and connection means 24 of the communication module 22 to the assembly 20.

[0024] In the example described, the connection means 24 are in the form of coaxial cables.

[0025] The communication module 22 is arranged in the payload 18 of the satellite 12. This module 22 is in the form of an electronic component connected, for example, to an on-board computer of the satellite 10.

[0026] In particular, the communication module 22 is capable of generating a transmission signal from, for example, the digital data transmitted to this module 22 by the on-board computer and of transmitting this transmission signal to the unit 20 through connecting means 24.

[0027] The communication module 22 is also capable of receiving electromagnetic signals received by the unit 20, transforming them into digital data and transmitting these digital data to the on-board computer.

[0028] The assembly 20 is arranged outside the satellite 10, that is, outside the satellite body 16, and comprises a reflector 30, a plurality of radiating elements 32A to 32F arranged opposite the reflector 30 and a box 34 connected on the one hand to the radiating elements 32A to 32F and on the other hand to the communication module 22 through the connection means 24.

[0029] The reflector 30 is known per se. Thus, for example, it has a parabolic shape oriented towards the earth's surface.

[0030] The radiating elements 32A to 32F are arranged, for example, substantially at the focus of the reflector 30. In this position, they are held by suitable support means known per se.

[0031] Each radiating element 32A to 32F is in the form of a horn for emitting and/or receiving electromagnetic signals. Each horn is elongated in shape and features a wide end and a narrow end. At least one of the horns, for example, the horn corresponding to the radiating element 32C, extends along an axis, called the horn axis X.

[0032] The horns have an identical shape or different shapes.

[0033] The horns as a whole are arranged on a flat surface of the box 34 facing the reflector 30 and are fixed, for example, on this surface by their narrow ends. The wide ends of the horns thus protrude with respect to this surface and form a radiating surface S visible in figure 3.

[0034] This radiating surface S is, for example, substantially flat and perpendicular to the horn axis X. In this case, all the horns extend along the horn axis X.

[0035] In the example described below, the horns, and therefore the radiating elements 32A to 32F, are six.

[0036] Figure 3 will further detail the contents of box 34.

[0037] It should be noted that in this figure 3, this content is illustrated in the form of a diagram, that is, without representing the actual physical shapes and positions of different elements.

[0038] In particular, referring to Figure 3, the box 34 comprises a transmission distribution network 41, a reception distribution network 42 and, for each radiating element 32A to 32F, a transmission path 43A to 43F that connects the radiating element 32A to 32F corresponding to the emission distribution network 41 and/or to the reception distribution network 42.

[0039] In the exemplary embodiment of Figure 3, the transmission paths 43A to 43F connect each radiating element 32A to 32F to the transmission distribution network 41 and to the reception distribution network 42.

[0040] For this, each transmission path 43A to 43F comprises a transmission waveguide 45A to 45F that connects the radiating element 32A to 32F corresponding to the transmission distribution network 41, and a reception waveguide 47A to 47F connecting the radiating element 32A to 32F corresponding to the receiving distribution network 42.

[0041] In addition, each transmission path 43A to 43F also comprises a radio frequency chain 49A to 49F that connects the reception 47A to 47F and emission 45A to 45F waveguides corresponding to the same radiating element 32A to 32F, to this element radiant 32A to 32F.

[0042] The emission distribution network 41 includes a plurality of emission ports connected to the radiating elements 32A to 32F through the corresponding emission waveguides 45A to 45F.

[0043] The emission distribution network 41 is also connected to the communication module 22 through the connection means 24 and is capable of receiving each electromagnetic signal coming from this communication module 22 to emit it through the radiating elements 32A at 32F in the form of elementary signals.

[0044] The emission distribution network 41 thus has an electronic component arranged between the radiating surface S and the reception distribution network 42.

[0045] In other words, the transmission distribution network 41 is arranged closer to the radiating surface S than the reception distribution network 42.

[0046] Furthermore, the emission waveguides 45A to 45F have a shorter length than that of the reception waveguides 47A to 47F.

[0047] Like the send distribution network 41, the receive distribution network 42 includes a plurality of receive ports connected to the radiating elements 32A to 32F through corresponding receive waveguides 47A to 47F.

[0048] The reception distribution network 42 is also connected to the communication module 22 through the connection means 24 and is capable of receiving elementary signals obtained from the corresponding radiating elements 32A to 32F, amplifying them and transmitting them to the communication module 22 through the connection means 24.

[0049] The reception distribution network 42 will be explained in more detail with reference to figure 4 which illustrates a section of a part of this reception distribution network 42.

[0050] In fact, in this figure 4, only two receive ports 50A and 50B can be seen respectively connected to the receive waveguides 47A and 47B.

[0051] In addition, as can also be seen in Figure 4, the reception distribution network 42 is in the form of a plate arranged transversely with respect to the horn axis X and has a first surface 51 oriented towards the radiating elements 32A at 32F and a second surface 52 opposite the first surface 51. The receiving ports 50A and 50B are arranged on the first surface 51 for example according to predetermined positions.

[0052] The plate is made for example in stacked layers.

[0053] The receiving distribution network 42 further includes a plurality of low noise amplifiers 55A to 55C disposed on the second surface 52 and interconnection means 56 disposed through the board and connecting each receive port 50A, 50B to at least one low noise amplifier 55A to 55C. In Figure 4 only three amplifiers 55A to 55C are seen.

[0054] Each low noise amplifier 55A to 55C is known per se and has, for example, an LNA (Low Noise Amplifier) type amplifier.

[0055] The interconnecting means 56 includes waveguides and a plurality of electromechanical switches 57A, 57B integrated in the waveguides. Each switch 57A, 57B can be controlled to switch the corresponding receive port 50A, 50B interface between at least two different low noise amplifiers 55A to 55C. In figure 4 only two switches 57A and 57B can be seen.

[0056] The control of the switches 57A, 57B is carried out, for example, by means of specific signals transmitted by the communication module 22 through the connection means 24.

[0057] According to a particularly advantageous embodiment, the interconnection means 56 form a redundancy loop that makes it possible to replace at least some damaged amplifiers 55A to 55C with redundant amplifiers 55A to 55C.

[0058] In particular, the redundancy loop and especially the arrangement of the corresponding waveguides through the board and the number of switches 57A, 57B, as well as the number of low noise amplifiers 55A to 55C, are adapted to ensure redundancy in N:N+P, where N indicates the total number of receive ports connected to radiating elements 32A to 32F and P indicates the number of low noise amplifier failures required for a receive port to be make it unusable.

[0059] In particular, in the exemplary embodiment of FIG. 3, the number N is equal to six and the number P is equal to three. In this case, the total number of low noise amplifiers is equal to nine.

[0060] Finally, the reception distribution network 42 also includes a thermal control system (not illustrated) that includes, for example, a plurality of channels filled with a fluid and arranged on the first and/or second surfaces 51 and 52, or well inside the plate.

[0061] This thermal control system makes it possible to generate an area near the reception distribution network 42 in which the temperature is controlled. This zone is called the cold zone as opposed to a zone, called the hot zone, located near the radiating elements 32A to 32F.

[0062] Furthermore, according to an exemplary embodiment, the waveguides and especially the receiving waveguides 47A to 47F are made of a heat-insulating material. This thus makes it possible to further isolate the receiving distribution network 42 from the radiating elements 32A to 32F.

[0063] More generally, according to an exemplary embodiment, the box 34 includes an independent thermal control system that couples a network of heat pipes to a radiator. This system is coupled, for example, to a thermal control system of the satellite 12.

[0064] It is thus understood that the present invention has a number of advantages.

[0065] In the first place, the arrangement of the reception distribution network and especially of the low-noise amplifiers as close as possible to the radiating elements makes it possible to considerably reduce the use of waveguides. This makes it possible to route the electromagnetic signals to the communication module through simple coaxial cables that are more flexible, less bulky and cheaper than the waveguides commonly used in these cases.

[0066] In addition, a thermal control implemented near the reception distribution network allows this network to be arranged as close as possible to the radiating elements without degrading the performance of the antenna.

[0067] In addition, the separation of the reception and transmission paths inside the box that contains the transmission and reception distribution networks allows the redundancy loop of the reception distribution network to be configured in the desired manner. In particular, in the example described, redundancy in N:N+P has been obtained.

[0068] Naturally, the present invention is not limited to the embodiment described above.

[0069] In particular, the invention remains applicable to any type of multi-beam antennas and not only to multi-beam antennas on board a satellite. Thus, it is possible to implement the invention in multi-beam antennas on board in any other type of mobile vehicle or to place them in a fixed manner, for example, on the earth's surface.

Claims (12)

1. Transmission and reception assembly (20) for a multi-beam antenna (12), including the antenna (12) in addition to a communication module (22), such that the assembly (22) comprises: - a plurality of radiating elements (32A,...,32F) forming a radiating surface (S), each radiating element (32A,...,32F) capable of emitting and receiving electromagnetic signals downstream of the surface radiant (S); - an emission distribution network (41) arranged upstream of the radiating surface (S) and including a plurality of emission ports, each emission port being connected to a radiating element (32A,...,32F) by an emission waveguide (45A,...,45F) and capable of emitting through the corresponding radiating element (32A,...,32F) an electromagnetic signal formed from an electromagnetic signal coming from the communication module ( 22); - a receiving distribution network (42) arranged upstream of the radiating surface (S) and including a plurality of receiving ports (50A, 50B), a plurality of low noise amplifiers (55A, 55B, 55C) and interconnection means (56) of each receiving port (50A, 50B) for at least one low noise amplifier (55A, 55B, 55C), such that each receiving port (50A, 50B) is connected to a radiating element (32A,...,32F) by a receiving waveguide (47A,...,47F) and is capable of receiving each electromagnetic signal coming from the corresponding radiating element (32A,...,32F) and transmitting it to the low noise amplifier (55A, 55B, 55C) associated to obtain an amplified electromagnetic signal intended for the communication module (22); the receiving distribution network (42) and the radiating elements (32A, 32F) are thermally decoupled, characterized in that: - the transmission distribution network (41) and the reception distribution network (42) are different from each other and are arranged in the same box (34) different from the communication module (22); and in that the receiving waveguides (47A,...,47F) are made of a heat insulating material capable of thermally isolating the low noise amplifiers (55A, 55B, 55C) from the radiating elements (32A,..., 32F). Assembly (20) according to claim 1, in which the receiving distribution network (42) is connected to the communication module (22) by coaxial cables. 3. Assembly (20) according to claim 1 or 2, in which the radiating elements (32A,...,32F) are in the form of horns, at least one of the horns being extended along a horn axis (X ). Assembly (20) according to claim 3, in which the receiving distribution network (42) is in the form of a plate arranged transversely with respect to the horn axis (X) and having a first surface (51) oriented towards the radiating elements (32A,...,32F) and a second surface (52) opposite the first surface (51), the receiving ports (50A, 50B) being arranged on the first surface (51) according to positions defaults. Assembly (20) according to claim 3 or 4, in which the transmission distribution network (41) is arranged between the radiating elements (32A,...,32F) and the reception distribution network (42) along the horn axis (X). An assembly (20) according to any of the preceding claims, wherein the interconnection means (56) includes a plurality of electromechanical switches (57A, 57B) controllable for switching the interconnection of each receive port (50A, 50B) between at least two different low noise amplifiers (55A, 55B, 55C). 7. Assembly (20) according to claim 6, in which: - the interconnection means (56) form a redundancy loop; - the redundancy loop and the number of low noise amplifiers (55A, 55B, 55C) are adapted to ensure redundancy in N:N+P, where N indicates the total number of receiving ports (50A, 50B) connected to the radiating elements (32A,...,32F) and P indicates the number of failures of the low noise amplifiers (55A, 55B, 55C) necessary for a receiving port (50A, 50B) to become unusable. Assembly (20) according to any of the preceding claims, in which the receiving distribution network (42) further includes a thermal control system. An assembly (20) according to claim 8 taken in combination with claim 4, wherein the thermal control system includes a plurality of channels filled with a fluid and arranged on the first and/or second surfaces (51, 52) . 10. Assembly (20) according to any of the preceding claims, further including a plurality of radio frequency chains (49A,...,49F), each radio frequency chain (49A,...,49F) being associated with an element radiating element (32A,...,32F) and connecting this radiating element (32A,...,32F) to the corresponding reception waveguide (47A,...,47F) and/or to the receiving waveguide emission (45A,...,45F) corresponding. 11. Multi-beam antenna (12) including a communication module (22) and a transmission and reception assembly (20), the transmission and reception assembly (20) being according to any of the preceding claims. 12. The antenna (12) of claim 11, wherein, when placed on a spacecraft (12), such that the spacecraft includes a payload, the box (34) comprising the broadcast distribution network (41) and the receive distribution network (42) is arranged outside the spacecraft (12) and the communication module (22) is arranged in the payload (18) of the spacecraft (12).